This invention relates to thermal barriers; particularly to multi-layer thermal barrier structures with compliant interlayer mechanical connections.
The working environment in a gas turbine engine is severe. Turbine components in the hot gas path are exposed to a high temperature, high velocity, corrosive, and sometimes abrasive environment. Coatings have always been required to protect and extend the lifetime of exposed components. Traditional thermal barrier coatings usually include abrasion resistant, thermally protective ceramic layers deposited over a metallic bond coat to create a thermal gradient between the hot gas path and the underlying structure. Lower working temperature leads to an extended lifetime. Thermal barrier coatings are generally applied directly to a component and offer necessary protection.
In certain instances, however, externally applied additional thermally protective structures can enhance thermal and abrasion resistance in specific regions of the hot gas path.